Methods and Apparatus for Combinatorial PECVD or PEALD

ABSTRACT

Apparatus and methods for depositing materials on a plurality of site-isolated regions on a substrate are provided. The deposition uses PECVD or PEALD. The apparatus include an inner chamber with an aperture and barrier that can be used to isolate the regions during the deposition and prevent the remaining portions of the substrate from being exposed to the deposition process. The process parameters for the deposition process are varied among the site-isolate regions in a combinatorial manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation application of U.S. patent application Ser. No.13/716,829, filed Dec. 17, 2012, which is herein incorporated byreference for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to methods and apparatuses forprocessing using a plasma source for surface treatment and layerformation.

BACKGROUND

Plasmas are widely used for a variety of treatment and layer depositiontasks in semiconductor fabrication and other thin film applications.These applications include subtractive processes such as waferprecleaning, contaminant removal, native oxide removal, photoresistremoval, plasma etching, as well as treatment processes such asoxidation, nitridation, or hydridation of a layer both during and afterformation, and deposition process such as plasma enhanced chemical vapordeposition (PECVD) or plasma enhanced atomic layer deposition (PEALD).“Remote” plasma sources are frequently used, where the plasma is locatedat some distance from the surface to be treated or substrate on which alayer is being formed. The distance allows some filtering of the chargedparticles in the plasma. For example, the density of electrons and ionscan be adjusted or removed from the generated plasma. “Direct” plasmasources are also used where the substrate is exposed to the plasma.

Heretofore, plasma sources have been used to provide uniform exposurefor entire substrates, and experimental studies of process variableshave required dedicating an entire wafer to each process condition to betested. What is needed is a system that allows systematic exploration ofprocess variables in a combinatorial manner with many variations on asingle substrate, especially for PECVD and PEALD applications. The mostpromising process parameters can then be extended to the processing ofentire substrates.

SUMMARY

The following summary of the disclosure is included in order to providea basic understanding of some aspects and features of the invention.This summary is not an extensive overview of the invention and as suchit is not intended to particularly identify key or critical elements ofthe invention or to delineate the scope of the invention. Its solepurpose is to present some concepts of the invention in a simplifiedform as a prelude to the more detailed description that is presentedbelow.

Methods and apparatus for depositing materials using PECVD or PEALD aredisclosed. The apparatus includes an outer chamber, a plasma source, andan inner chamber enclosing a substrate support. The inner chamber has atop surface parallel to the surface of the substrate support, a bottomsurface parallel to the top surface and disposed below the substratesupport, and one or more side walls. An aperture is disposed in the topsurface of the inner chamber and is operable to provide site-isolatedexposure of plasma from the plasma source to a site-isolated region on asubstrate. The aperture is disposed between the plasma source and thesubstrate and has an area less than that of the substrate. A barrier canbe positioned near the edges of the aperture, extending down from thetop surface of the inner chamber toward the substrate, and separatedfrom the substrate by a small gap, typically less than about 0.5 mm. Thebarrier can define the boundaries of the site-isolated region on thesubstrate. A gas purge system can be provided from a plurality of flowoutlets at the edge of the substrate support. The gas purge system canprovide a gas flow into the site-isolated region through the small gapand out of the site-isolated region through the aperture. A substrateheater can be mounted in the substrate support. A transport system movesthe substrate support and is capable of positioning the substrate suchthat the site-isolated region can be located anywhere on the substrate.

Methods of depositing materials on a plurality of site-isolated regionsusing PECVD or PEALD are provided. The methods comprise depositingmaterial using PECVD or PEALD on a first site-isolated region of asurface under a first set of process parameters, depositing materialusing PECVD or PEALD on a second site-isolated region of the surface ofthe substrate under a second set of process parameters, and varying thefirst set and second set of process parameters in a combinatorialmanner. The first set and second set of process parameters include oneor more of source gases for the plasma generator, plasma filteringparameters, exposure time, gas flow rate, frequency, plasma generatorpower, plasma generation method, chamber pressure, substratetemperature, distance between plasma source and substrate, substratebias voltage, or combinations thereof. The depositing can be controlledby an aperture in a plate disposed between the plasma source and thesubstrate. The aperture has an area less than that of the substrate. Thedepositing can be further controlled by placing a barrier near the edgesof the aperture, wherein the barrier extends from the aperture plate tothe substrate surface and is separated by a small gap from the substratesurface. The depositing can also be controlled by a gas purge systemthat provides a flow of gas into the site-isolated region through thesmall gap and out of the site-isolated region through the aperture.

The method can be extended by depositing material using PECVD or PEALDon a third site-isolated region of the substrate under a third set ofprocess parameters, and more generally, by depositing material usingPECVD or PEALD on a plurality of site-isolated regions of the substrateunder a plurality of different sets of process parameters. The substratecan be analyzed to evaluate the effect of the different processparameters on the substrate. Plasma deposition process parameters can bevaried in a combinatorial manner. Plasma deposition process parametersinclude one or more of source gases for the plasma generator, plasmafiltering parameters, exposure time, gas flow rate, frequency, plasmagenerator power, plasma generation method, chamber pressure, substratetemperature, distance between plasma source and substrate, substratebias voltage, or combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. The drawings are not to scale and the relative dimensionsof various elements in the drawings are depicted schematically and notnecessarily to scale.

The techniques of the present invention can readily be understood byconsidering the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a schematic diagram for implementing combinatorialprocessing and evaluation.

FIG. 2 presents a schematic diagram for illustrating various processsequences using combinatorial processing and evaluation.

FIG. 3 illustrates a processing system enabling combinatorialprocessing.

FIG. 4 illustrates an apparatus enabling combinatorial processing usingPECVD or PEALD.

FIG. 5 illustrates an apparatus enabling combinatorial processing usingPECVD or PEALD.

FIG. 6 presents a flow chart illustrating the steps of methods accordingto some embodiments.

DETAILED DESCRIPTION

A detailed description of one or more embodiments is provided belowalong with accompanying figures. The detailed description is provided inconnection with such embodiments, but is not limited to any particularexample. The scope is limited only by the claims and numerousalternatives, modifications, and equivalents are encompassed. Numerousspecific details are set forth in the following description in order toprovide a thorough understanding. These details are provided for thepurpose of example and the described techniques may be practicedaccording to the claims without some or all of these specific details.For the purpose of clarity, technical material that is known in thetechnical fields related to the embodiments has not been described indetail to avoid unnecessarily obscuring the description.

Before various embodiments are described in detail, it is to beunderstood that unless otherwise indicated, this invention is notlimited to specific layer compositions or surface treatments. It is alsoto be understood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to limit thescope of the present invention.

It must be noted that as used herein and in the claims, the singularforms “a,” “and” and “the” include plural referents unless the contextclearly dictates otherwise. Thus, for example, reference to “a layer”includes two or more layers, and so forth.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range, and any other stated or intervening value in thatstated range, is encompassed within the invention. The upper and lowerlimits of these smaller ranges may independently be included in thesmaller ranges, and are also encompassed within the invention, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the invention. Theterm “about” generally refers to ±10% of a stated value.

The term “site-isolated” as used herein refers to providing distinctprocessing conditions, such as controlled temperature, flow rates,chamber pressure, processing time, plasma composition, and plasmaenergies. Site isolation may provide complete isolation between regionsor relative isolation between regions. Preferably, the relativeisolation is sufficient to provide a control over processing conditionswithin ±10%, within ±5%, within ±2%, within ±1%, or within ±0.1% of thetarget conditions. Where one region is processed at a time, adjacentregions are generally protected from any exposure that would alter thesubstrate surface in a measurable way.

The term “site-isolated region” is used herein to refer to a localizedarea on a substrate which is, was, or is intended to be used forprocessing or formation of a selected material. The region can includeone region and/or a series of regular or periodic regions predefined onthe substrate. The region may have any convenient shape, e.g., circular,rectangular, elliptical, wedge-shaped, etc. In the semiconductor field,a region may be, for example, a test structure, single die, multipledies, portion of a die, other defined portion of substrate, or anundefined area of a substrate, e.g., blanket substrate which is definedthrough the processing.

The term “substrate” as used herein may refer to any workpiece on whichformation or treatment of material layers is desired. Substrates mayinclude, without limitation, silicon, silica, sapphire, zinc oxide, SiC,AlN, GaN, Spinel, coated silicon, silicon on oxide, silicon carbide onoxide, glass, gallium nitride, indium nitride and aluminum nitride, andcombinations (or alloys) thereof. The term “substrate” or “wafer” may beused interchangeably herein. Semiconductor wafer shapes and sizes canvary and include commonly used round wafers of 2″, 4″, 200 mm, or 300 mmin diameter.

The term “remote plasma source” as used herein refers to a plasma (e.g.,an rf or microwave generated plasma) located at a distance from adeposition or treatment location sufficient to allow some filtering ofthe plasma components. For example, the density of ions and electronscan be adjusted by distance, and electrons and ions can also be filteredout using suitable electrode configurations, such as a grounded metalshowerhead so that only atomic or molecular radicals reach thesubstrate.

Systems and methods for High Productivity Combinatorial (HPC) processingare described in U.S. Pat. No. 7,544,574 filed on Feb. 10, 2006, U.S.Pat. No. 7,824,935 filed on Jul. 2, 2008, U.S. Pat. No. 7,871,928 filedon May 4, 2009, U.S. Pat. No. 7,902,063 filed on Feb. 10, 2006, and U.S.Pat. No. 7,947,531 filed on Aug. 28, 2009 which are all hereinincorporated by reference. Systems and methods for HPC processing arefurther described in U.S. patent application Ser. No. 11/352,077 filedon Feb. 10, 2006, claiming priority from Oct. 15, 2005, U.S. patentapplication Ser. No. 11/419,174 filed on May 18, 2006, claiming priorityfrom Oct. 15, 2005, U.S. patent application Ser. No. 11/674,132 filed onFeb. 12, 2007, claiming priority from Oct. 15, 2005, and U.S. patentapplication Ser. No. 11/674,137 filed on Feb. 12, 2007, claimingpriority from Oct. 15, 2005 which are all herein incorporated byreference.

HPC processing techniques have been successfully adapted to wet chemicalprocessing such as etching and cleaning. HPC processing techniques havealso been successfully adapted to deposition processes such as physicalvapor deposition (PVD), atomic layer deposition (ALD), and chemicalvapor deposition (CVD).

The present invention is described in one or more embodiments in thefollowing description with reference to the Figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in exemplary terms which include a best mode for achieving theinvention's objectives, it will be appreciated by those skilled in theart that it is intended to cover alternatives, modifications, andequivalents as may be included within the spirit and scope of theinvention as defined by the appended claims and their equivalents assupported by the following disclosure and drawings.

Embodiments of the present invention provide a system for systematicexploration of plasma treatment process variables in a combinatorialmanner with the possibility of performing many variations on a singlesubstrate. The combinatorial processing permits a single substrate to besystematically explored using different plasma processing conditions,and reduces or eliminates variables that interfere with researchquality. The apparatuses and methods disclosed herein permit thesystematic exploration of plasma treatments on a single substrate usingcombinatorial methods, and removes the run to run variability andinconsistencies between substrates that hamper research and optimizationof process variables.

FIG. 1 illustrates a schematic diagram, 100, for implementingcombinatorial processing and evaluation using primary, secondary, andtertiary screening. The schematic diagram, 100, illustrates that therelative number of combinatorial processes run with a group ofsubstrates decreases as certain materials and/or processes are selected.Generally, combinatorial processing includes performing a large numberof processes during a primary screen, selecting promising candidatesfrom those processes, performing the selected processing during asecondary screen, selecting promising candidates from the secondaryscreen for a tertiary screen, and so on. In addition, feedback fromlater stages to earlier stages can be used to refine the successcriteria and provide better screening results.

For example, thousands of materials are evaluated during a materialsdiscovery stage, 102. Materials discovery stage, 102, is also known as aprimary screening stage performed using primary screening techniques.Primary screening techniques may include dividing substrates intocoupons and depositing materials using varied processes. The materialsare then evaluated, and promising candidates are advanced to thesecondary screen, or materials and process development stage, 104.Evaluation of the materials is performed using metrology tools such aselectronic testers and imaging tools (i.e., microscopes).

The materials and process development stage, 104, may evaluate hundredsof materials (i.e., a magnitude smaller than the primary stage) and mayfocus on the processes used to deposit or develop those materials.Promising materials and processes are again selected, and advanced tothe tertiary screen or process integration stage, 106, where tens ofmaterials and/or processes and combinations are evaluated. The tertiaryscreen or process integration stage, 106, may focus on integrating theselected processes and materials with other processes and materials.

The most promising materials and processes from the tertiary screen areadvanced to device qualification, 108. In device qualification, thematerials and processes selected are evaluated for high volumemanufacturing, which normally is conducted on full substrates withinproduction tools, but need not be conducted in such a manner. Theresults are evaluated to determine the efficacy of the selectedmaterials and processes. If successful, the use of the screenedmaterials and processes can proceed to pilot manufacturing, 110.

The schematic diagram, 100, is an example of various techniques that maybe used to evaluate and select materials and processes for thedevelopment of new materials and processes. The descriptions of primary,secondary, etc. screening and the various stages, 102-110, are arbitraryand the stages may overlap, occur out of sequence, be described and beperformed in many other ways.

This application benefits from High Productivity Combinatorial (HPC)techniques described in U.S. patent application Ser. No. 11/674,137filed on Feb. 12, 2007 which is hereby incorporated for reference in itsentirety. Portions of the '137 application have been reproduced below toenhance the understanding of the present invention.

While the combinatorial processing varies certain materials, hardwaredetails, or process sequences, the composition or thickness of thelayers or structures or the actions, such as cleaning, surfacepreparation, deposition, surface treatment, etc. is substantiallyuniform through each discrete region. Furthermore, while differentmaterials or processes may be used for corresponding layers or steps inthe formation of a structure in different regions of the substrateduring the combinatorial processing, the application of each layer oruse of a given process is substantially consistent or uniform throughoutthe different regions in which it is intentionally applied. Thus, theprocessing is uniform within a region (inter-region uniformity) andbetween regions (intra-region uniformity), as desired. It should benoted that the process can be varied between regions, for example, wherea thickness of a layer is varied or a material may be varied between theregions, etc., as desired by the design of the experiment.

The result is a series of regions on the substrate that containstructures or unit process sequences that have been uniformly appliedwithin that region and, as applicable, across different regions. Thisprocess uniformity allows comparison of the properties within and acrossthe different regions such that the variations in test results are dueto the varied parameter (e.g., materials, unit processes, unit processparameters, hardware details, or process sequences) and not the lack ofprocess uniformity. In the embodiments described herein, the positionsof the discrete regions on the substrate can be defined as needed, butare preferably systematized for ease of tooling and design ofexperimentation. In addition, the number, variants and location ofstructures within each region are designed to enable valid statisticalanalysis of the test results within each region and across regions to beperformed.

FIG. 2 is a simplified schematic diagram illustrating a generalmethodology for combinatorial process sequence integration that includessite-isolated processing and/or conventional processing in accordancewith one embodiment of the invention. In one embodiment, the substrateis initially processed using conventional process N. In one exemplaryembodiment, the substrate is then processed using site-isolated processN+1. During site-isolated processing, an HPC module may be used, such asthe HPC module described in U.S. patent application Ser. No. 11/352,077filed on Feb. 10, 2006. The substrate can then be processed usingsite-isolated process N+2, and thereafter processed using conventionalprocess N+3. Testing is performed and the results are evaluated. Thetesting can include physical, chemical, acoustic, magnetic, electrical,optical, etc. tests. From this evaluation, a particular process from thevarious site-isolated processes (e.g. from steps N+1 and N+2) may beselected and fixed so that additional combinatorial process sequenceintegration may be performed using site-isolated processing for eitherprocess N or N+3. For example, a next process sequence can includeprocessing the substrate using site-isolated process N, conventionalprocessing for processes N+1, N+2, and N+3, with testing performedthereafter.

It should be appreciated that various other combinations of conventionaland combinatorial processes can be included in the processing sequencewith regard to FIG. 2. That is, the combinatorial process sequenceintegration can be applied to any desired segments and/or portions of anoverall process flow. Characterization, including physical, chemical,acoustic, magnetic, electrical, optical, etc. testing, can be performedafter each process operation, and/or series of process operations withinthe process flow as desired. The feedback provided by the testing isused to select certain materials, processes, process conditions, andprocess sequences and eliminate others. Furthermore, the above processflows can be applied to entire monolithic substrates, or portions of themonolithic substrates.

Under combinatorial processing operations the processing conditions atdifferent regions can be controlled independently. Consequently, processmaterial amounts, reactant species, processing temperatures, processingtimes, processing pressures, processing flow rates, processing powers,processing reagent compositions, the rates at which the reactions arequenched, deposition order of process materials, process sequence steps,hardware details, etc., can be varied from region to region on thesubstrate. Thus, for example, when exploring materials, a processingmaterial delivered to a first and second region can be the same ordifferent. If the processing material delivered to the first region isthe same as the processing material delivered to the second region, thisprocessing material can be offered to the first and second regions onthe substrate at different concentrations. In addition, the material canbe deposited under different processing parameters. Parameters which canbe varied include, but are not limited to, process material amounts,reactant species, processing temperatures, processing times, processingpressures, processing flow rates, processing powers, processing reagentcompositions, the rates at which the reactions are quenched, atmospheresin which the processes are conducted, the order in which materials aredeposited, hardware details of the gas distribution assembly, etc. Itshould be appreciated that these process parameters are exemplary andnot meant to be an exhaustive list as other process parameters commonlyused with plasma exposure systems may be varied.

As mentioned above, within a region, the process conditions aresubstantially uniform, in contrast to gradient processing techniqueswhich rely on the inherent non-uniformity of the material deposition.That is, the embodiments, described herein locally perform theprocessing in a conventional manner, e.g., substantially consistent andsubstantially uniform, while globally over the substrate, the materials,processes, and process sequences may vary. Thus, the testing will findoptimums without interference from process variation differences betweenprocesses that are meant to be the same. It should be appreciated that aregion may be adjacent to another region in one embodiment or theregions may be isolated and, therefore, non-overlapping. When theregions are adjacent, there may be a slight overlap wherein thematerials or precise process interactions are not known, however, aportion of the regions, normally at least 50% or more of the area, isuniform and all testing occurs within that region. Further, thepotential overlap is only allowed with material of processes that willnot adversely affect the result of the tests. Both types of regions arereferred to herein as regions or discrete regions.

Substrates may be a conventional round 200 mm, 300 mm, or any otherlarger or smaller substrate/wafer size. In other embodiments, substratesmay be square, rectangular, or other shape. One skilled in the art willappreciate that substrate may be a blanket substrate, a coupon (e.g.,partial wafer), or even a patterned substrate having predefined regions.In some embodiments, a substrate may have regions defined through theprocessing described herein.

Software is provided to control the process parameters for each waferfor the combinatorial processing. The process parameters compriseselection of one or more source gases for the plasma generator, plasmafiltering parameters, exposure time, substrate temperature, power,frequency, plasma generation method, substrate bias, pressure, gas flow,or combinations thereof.

FIG. 3 is a simplified schematic diagram illustrating an integrated highproductivity combinatorial (HPC) system in accordance with someembodiments of the invention. The HPC system includes a frame 300supporting a plurality of processing modules. It will be appreciatedthat frame 300 may be a unitary frame in accordance with someembodiments. In some embodiments, the environment within frame 300 iscontrolled. A load lock 302 provides access into the plurality ofmodules of the HPC system. A robot 314 provides for the movement ofsubstrates (and masks) between the modules and for the movement into andout of the load lock 302. Modules 304-312 may be any set of modules andpreferably include one or more combinatorial modules. For example,module 304 may be an orientation/degassing module, module 306 may be aclean module, either plasma or non-plasma based, modules 308 and/or 310may be combinatorial/conventional dual purpose modules. Module 312 mayprovide conventional clean or degas as necessary for the experimentdesign.

Any type of chamber or combination of chambers may be implemented andthe description herein is merely illustrative of one possiblecombination and not meant to limit the potential chamber or processesthat can be supported to combine combinatorial processing orcombinatorial plus conventional processing of a substrate or wafer. Insome embodiments, a centralized controller, i.e., computing device 316,may control the processes of the HPC system. Further details of onepossible HPC system are described in U.S. application Ser. Nos.11/672,478 and 11/672,473, the entire disclosures of which are hereinincorporated by reference. In a HPC system, a plurality of methods maybe employed to deposit material upon a substrate employing combinatorialprocesses.

Plasmas are widely used for a variety of treatment, etching, and layerdeposition (i.e. PECVD or PEALD) tasks in semiconductor fabrication.These applications include treatment processes such as oxidation,nitridation, or hydridation of a layer both during and after formation,subtractive processes such as wafer precleaning, contaminant removal,native oxide removal, photoresist removal, and deposition applicationssuch as thin films, spacers, isolation materials, conductors, and thelike. “Remote” plasma sources are frequently used, where the plasma islocated at some distance from the surface to be treated or substrate onwhich a layer is to be formed. The distance allows some adjusting of thecharged particles in the plasma. For example, the density of ions andelectrons can be adjusted by distance, the electrons and ions can beremoved from the generated plasma using suitable electrodeconfigurations such as a grounded metal showerhead, so that, forexample, only atomic radicals and molecule radicals (but not ions) reachthe substrate. However, “direct” plasma sources can also be used, wherethe substrate is exposed to the plasma.

The plasma generator can use any known means of coupling energy intoatoms or molecules to ionize them and create a plasma. The energy sourcecan be, for example, electromagnetic energy such as microwaves, radiofrequency energy, or lasers.

Typically, systems using plasma sources were designed to treat theentire area of a substrate, such as a 300 mm wafer. Combinatorialprocessing is difficult and expensive when the entire area of asubstrate can only receive a single process variation. Some embodimentsovercome this limitation by providing a plasma source, an associatedsubstrate positioning system, and a site isolation system that allows aselected region of a substrate to be processed while the remainingregions of the substrate are protected from exposure to the plasma andreactive radical species unless or until such exposure is intended.

Accordingly, an apparatus for combinatorial processing using plasmaexposure (e.g. PECVD or PEALD) of a substrate is disclosed. Theapparatus comprises an outer chamber containing: a plasma source, anaperture allowing exposure of a site-isolated region of the substrate toplasma from the plasma source, and a transport system comprising asubstrate support and capable of positioning the substrate such that thesite-isolated region can be located anywhere on the substrate. Theaperture has an area less than that of the substrate, so that aplurality of site-isolated regions on a single substrate can be exposedto a variety of plasma processing conditions. A barrier or barriers anda gas purge system operate to provide exposure to plasma and reactiveradical species within the site-isolated region, preventing exposure ofregions of the substrate outside the area exposed to plasma and reactiveradical species through the aperture. The plasma exposure processparameters can be varied in a combinatorial manner. The plasma exposureprocess parameters comprise one or more of source gases for the plasmagenerator, plasma filtering parameters, exposure time, gas flow rate,frequency, plasma generator power, plasma generation method, chamberpressure, substrate temperature, distance between plasma source andsubstrate, substrate bias voltage, or combinations thereof.

In some embodiments, the apparatus further comprises an inner chamber,contained within the outer chamber and enclosing the substrate and thesubstrate support. A “process kit” can be defined comprising the innerchamber, substrate, and substrate support. The inner chamber comprises atop surface parallel to and in close proximity to the substrate, abottom surface below the substrate support, and one or more side walls.The dimensions of the inner chamber parallel to the substrate are suchthat any desired region on the substrate can be positioned under theaperture, (i.e., there is sufficient space available in the innerchamber to accommodate the substrate and substrate support in anyconfiguration necessary to provide access to the substrate through theaperture).

The aperture is preferably located in the top surface of the innerchamber with the barrier positioned near the edges of the aperture. Thebarrier can extend down from the top surface of the inner chamber towardthe substrate, to provide more restriction to the flow of plasma and/orreactive radical species toward the remaining regions of the substrate.The barrier can be separated from the substrate by a small gap. The gapbetween the barrier and the substrate can be set to a distance of about0.5 mm or less to exclude plasma and reactive radical species fromreaching areas of the substrate outside the aperture and barrier. Insome embodiments, the substrate support can comprise a substrate heatermounted in the substrate support for providing an independenttemperature regulation as a process parameter that can be varied in acombinatorial manner.

The apparatus can include a gas purge system that comprises a pluralityof flow outlets located at the edge of the substrate support. The gaspurge system provides a gas flow into the site-isolated region throughthe small gap between the barrier and the substrate and out of thesite-isolated region through the aperture, preventing plasma and/orreactive radical species from leaking past the barrier and affecting theprotected regions of the substrate. The barrier or barriers and gaspurge system can work together with the aperture to control exposure ofplasma and reactive radical species to the substrate surface.

FIG. 4 illustrates the overall layout of some embodiments of a systemenabling combinatorial processing using a plasma source. A discussion ofthe system may be found in co-owned U.S. patent application Ser. No.13/328,129 filed on Dec. 16, 2011 which is herein incorporated byreference for all purposes. Portions of the '129 application areincluded herein to enhance the understanding of the present disclosure.An outer process chamber 400 is provided. A plasma source 402 is mountedon a chamber lid 404 either directly as illustrated or through a shortflange. The plasma source 402 may be a remote plasma source or may be adirect plasma source. The configuration illustrated in FIG. 4corresponds to a remote plasma source. The plasma 406 is entrained intoa central gas flow 408 which is directed toward an aperture 410. Theaperture is in close proximity to a substrate 412. A substratepositioning system 414 can position any region on the substrate 412directly under the aperture 410. As illustrated in FIG. 4, the substratepositioning system can provide two displaced axes of rotation 416 and418. The two-axis rotation configuration illustrated can provide 360° ofrotation for the upper rotation (providing an angular coordinate) and60° of rotation for the lower axis (approximating a radial coordinate)to provide all possible substrate positions. Alternatively, otherpositioning systems such as X-Y translators can also be used. Inaddition, substrate support 422 may move in a vertical direction. Itshould be appreciated that the rotation and movement in the verticaldirection may be achieved through known drive mechanisms which includemagnetic drives, linear drives, worm screws, lead screws, adifferentially pumped rotary feed through drive, etc.

An inner chamber (also called a “process kit”) 420 provides an enclosurefor the substrate 412 and the substrate support 422. Substrate support422 can be configured to hold a substrate 412 thereon, and can be anyknown substrate support, including but not limited to a vacuum chuck,electrostatic chuck, or other known mechanisms. The shape can beselected to conveniently enclose the substrate and substrate support inall positions used; for example, it can be cylindrical. The innerchamber 420 comprises a top surface 430 parallel to the substrate 412, abottom surface 432 below the substrate support 422, and one or more sidewalls 434. The top surface 430 need not be positioned close thesubstrate surface. The substrate 412 is shown mounted on substratesupport 422. The inner chamber 420 is typically made from a materialsuch as quartz or ceramic that is mechanically and chemically stable atprocess temperatures. The inner chamber 420 can be made of two differentmaterials, with a center portion made of quartz or ceramic, and the edgeportion made of metal. The X-Y extent of the inner chamber 420 is largeenough to accommodate the substrate 412 in any position that can beachieved using the substrate positioning system.

The substrate support 422 can include a substrate heater (e.g.,resistive or inductive) and can be sized to be larger than the largestsubstrate to be processed. Substrate temperatures for most plasmaapplications are less than 500 C, although any suitable heater power andrange of temperature control. The substrate support 422 can also beconfigured to provide a gas purge flow 424, for example from the edgesof the support, using argon, helium, or any other gas that is notreactive under the process conditions.

The aperture 410 defines the area of a site-isolated region whereexposure to a plasma or reactive species occurs. Barrier 426 near theedges of the aperture provides control over plasma exposure, and servesto restrict plasma or reactive radical species access to regions outsidethe area immediately under the aperture 410. The position, shape, andheight of barrier 426 can be chosen to provide maximal protection ofareas of the substrate 412 for which plasma exposure is not desired.Barrier 426 can be made from a high-temperature O-ring material such asKALREZ® fluoropolymer or a refractory material such as quartz orceramic. In some embodiments, the barrier is circular; the barrier doesnot have to be any particular shape, but most generally is compatiblewith the shape of the aperture 410. The barrier 426 can be positionedwith a small gap (typically less than 0.5 mm) to the substrate 412, andthe gas purge flow 424 can be adjusted so that any gas leakage under thebarrier 426 is directed into the site-isolated region and out throughthe aperture 410.

The aperture shape and size can be varied according to the needs ofparticular combinatorial experiments. Typical shapes are round, square,or rectangular with linear extents of about 10 to about 25 mm, althoughother shapes and sizes are possible, for example about 1 to about 65 mm.Further experimental design flexibility can be provided by usingpatterned apertures with multiple openings.

FIG. 5 illustrates the overall layout of some embodiments of a systemenabling combinatorial processing using a plasma source. An outerprocess chamber 500 is provided. A plasma source 502 is mounted on achamber lid 504 either directly as illustrated or through a shortflange. The plasma source 502 may be a remote plasma source or may be adirect plasma source. The configuration illustrated in FIG. 5corresponds to a direct plasma source. The plasma 506 is formed betweena showerhead 536 and an inner chamber 520 including an aperture 510. Theshowerhead serves to distribute the gases 508 evenly across the regionof the inner chamber that includes the aperture. The plasma may beignited by applying power to either the showerhead or the substratesupport. The aperture is in close proximity to a substrate 512. Asubstrate positioning system 514 can position any region on thesubstrate 512 directly under the aperture 510. As illustrated in FIG. 5,the substrate positioning system can provide two displaced axes ofrotation 516 and 518. The two-axis rotation configuration illustratedcan provide 360° of rotation for the upper rotation (providing anangular coordinate) and 60° of rotation for the lower axis(approximating a radial coordinate) to provide all possible substratepositions. Alternatively, other positioning systems such as X-Ytranslators can also be used. In addition, substrate support 522 maymove in a vertical direction. It should be appreciated that the rotationand movement in the vertical direction may be achieved through knowndrive mechanisms which include magnetic drives, linear drives, wormscrews, lead screws, a differentially pumped rotary feed through drive,etc.

An inner chamber (also called a “process kit”) 520 provides an enclosurefor the substrate 512 and the substrate support 522. Substrate support522 can be configured to hold a substrate 512 thereon, and can be anyknown substrate support, including but not limited to a vacuum chuck,electrostatic chuck, or other known mechanisms. The shape can beselected to conveniently enclose the substrate and substrate support inall positions used; for example, it can be cylindrical. The innerchamber 520 comprises a top surface 530 parallel to the substrate 512, abottom surface 532 below the substrate support 522, and one or more sidewalls 534. The top surface 530 need not be positioned close thesubstrate surface. The substrate 512 is shown mounted on substratesupport 522. The inner chamber 520 is typically made from a materialsuch as quartz or ceramic that is mechanically and chemically stable atprocess temperatures. The inner chamber 520 can be made of two differentmaterials, with a center portion made of quartz or ceramic, and the edgeportion made of metal. The X-Y extent of the inner chamber 520 is largeenough to accommodate the substrate 512 in any position that can beachieved using the substrate positioning system.

The substrate support 522 can include a substrate heater (e.g.,resistive or inductive) and can be sized to be larger than the largestsubstrate to be processed. Substrate temperatures for most plasmaapplications are less than 500 C, although any suitable heater power andrange of temperature control. The substrate support 522 can also beconfigured to provide a gas purge flow 524, for example from the edgesof the support, using argon, helium, or any other gas that is notreactive under the process conditions.

The aperture 510 defines the area of a site-isolated region whereexposure to a plasma or reactive species occurs. Barrier 526 near theedges of the aperture provides control over plasma exposure, and servesto restrict plasma or reactive radical species access to regions outsidethe area immediately under the aperture 510. The position, shape, andheight of barrier 526 can be chosen to provide maximal protection ofareas of the substrate 512 for which plasma exposure is not desired.Barrier 526 can be made from a high-temperature O-ring material such asKALREZ® fluoropolymer or a refractory material such as quartz orceramic. In some embodiments, the barrier is circular; the barrier doesnot have to be any particular shape, but most generally is compatiblewith the shape of the aperture 510. The barrier 526 can be positionedwith a small gap (typically less than 0.5 mm) to the substrate 512, andthe gas purge flow 524 can be adjusted so that any gas leakage under thebarrier 526 is directed into the site-isolated region and out throughthe aperture 510.

The aperture shape and size can be varied according to the needs ofparticular combinatorial experiments. Typical shapes are round, square,or rectangular with linear extents of about 10 to about 25 mm, althoughother shapes and sizes are possible, for example about 1 to about 65 mm.Further experimental design flexibility can be provided by usingpatterned apertures with multiple openings.

In some embodiments, methods of combinatorially depositing materials byPECVD are provided. The methods are illustrated in FIG. 6. In step 602 asubstrate is provided. The methods comprise depositing material on asite-isolated region of the substrate using PECVD or PEALD under a firstset of process parameters in step 604. Step 606 determines if materialhas been deposited on all of the site-isolated regions. If not, then thesubstrate is moved 608 to expose a new site-isolated region to theaperture as discussed previously. Step 604 is repeated to depositmaterial on a second site-isolated region of the substrate using PECVDor PEALD under a second set of process parameters. During eachdeposition, the remaining area (the unexposed area) of the substrate isprotected from exposure to the plasma or reactive species. The processparameters can be varied in a combinatorial manner. Typically, theprocess parameters comprise one or more of source gases for the plasmagenerator, plasma filtering parameters, exposure times, gas flow rates,frequencies, plasma generator powers, plasma generation methods, chamberpressures, substrate temperatures, distances between plasma source andsubstrate, substrate bias voltages, or combinations thereof. Thissequence is repeated until material has been deposited on all of thesite-isolated regions on the substrate 610. After material has beendeposited on all of the site-isolated regions of the substrate underdifferent PECVD or PEALD processing parameters, the substrate isanalyzed to evaluate the effect of the different process parameters onthe material deposited in each of the site-isolated regions.

Process times for deposition can vary. Typical process times vary from afew seconds to a few minutes. In some embodiments, the process times arepreferably set by turning the plasma generator on and off. In someembodiments, the plasma generator is left on, and a shutter can beopened to start exposure, and the shutter can be closed to stopexposure. The shutter can be located anywhere between the plasma source402/502 and the aperture 410/510.

Although the foregoing examples have been described in some detail forpurposes of clarity of understanding, the invention is not limited tothe details provided. There are many alternative ways of implementingthe invention. The disclosed examples are illustrative and notrestrictive.

What is claimed:
 1. An apparatus for deposition of material on asubstrate, the apparatus comprising: a first chamber; a second chamber;a plasma source; a substrate support; a substrate positioning system;wherein the second chamber, the plasma source, the substrate support,and the substrate positioning system are disposed within the firstchamber; wherein the second chamber encloses the substrate support;wherein the second chamber comprises a top surface being parallel to atop surface of the substrate support; wherein the second chambercomprises a bottom surface being parallel to the top surface of thesubstrate support, the substrate support being positioned between thetop surface and the bottom surface of the second chamber; wherein thesecond chamber comprises one or more sidewalls connecting the topsurface of the second chamber to the bottom surface of the secondchamber; wherein the top surface of the second chamber comprises anaperture; wherein an area of the aperture is less than an area of thesubstrate support; wherein the aperture is operable to allowsite-isolated deposition of a material using plasma enhanced chemicalvapor deposition (PECVD) or plasma enhanced atomic layer deposition(PEALD) in a plurality of site-isolated regions on the substrate; andwherein the substrate positioning system is operable to align any areaof the substrate support with respect to the aperture such that any areaof the substrate support corresponds to one of the plurality ofsite-isolated regions on the substrate.
 2. The apparatus of claim 1,further comprising a plasma source operable to vary plasma processparameters during the PECVD and the PEALD in a combinatorial manneramong the plurality of site-isolated regions.
 3. The apparatus of claim2, wherein the plasma process parameters comprise at least one of sourcegases for a plasma generator, plasma filtering parameters, exposuretime, gas flow rate, frequency, plasma generator power, plasmageneration method, chamber pressure, substrate temperature, distancebetween plasma source and substrate, substrate bias voltage, orcombinations thereof.
 4. The apparatus of claim 2, wherein the plasmasource is operable to ignite plasma within the first chamber and outsideof the second chamber.
 5. The apparatus of claim 2, further comprising ashowerhead disposed within the first chamber and outside of the secondchamber.
 6. The apparatus of claim 2, wherein the plasma source is aremote plasma source.
 7. The apparatus of claim 1, further comprising abarrier positioned at edges of the aperture, wherein the barrier extendsdown from the top surface of the second chamber toward the substratesupport, and wherein, during the PECVD and the PEALD, the barrier isoperable to restrict plasma or reactive radical species access tosite-isolated regions of the plurality of site-isolated regions on thesubstrate not aligned with the aperture.
 8. The apparatus of claim 7,wherein, during the PECVD and the PEALD, the barrier is separated fromthe substrate by a gap, wherein the gap is less than 0.5 mm.
 9. Theapparatus of claim 8, wherein the gap control a flow of process gassesinto one of the plurality of site-isolated regions defined by thebarrier.
 10. The apparatus of claim 7, wherein the barrier defines aboundary of each the plurality of site-isolated regions on thesubstrate.
 11. The apparatus of claim 7, wherein the barrier is formedfrom one of a fluoropolymer, quartz, or ceramic.
 12. The apparatus ofclaim 1, further comprising a gas purge system comprising a plurality offlow outlets at an edge of the substrate support.
 13. The apparatus ofclaim 12, wherein the gas purge system is operable to provide a gas flowinto each of the plurality of site-isolated regions through a gapbetween the substrate and a portion of the second chamber, and whereinthe gas purge system is operable to provide a gas flow out of each ofthe plurality of site-isolated regions through the aperture.
 14. Theapparatus of claim 1, further comprising a shutter disposed between thefirst chamber and the aperture.
 15. The apparatus of claim 1, whereinthe substrate positioning system is operable to rotate the substratesupport about two parallel non-collinear axes.
 16. The apparatus ofclaim 1, wherein the substrate positioning system comprises linear X-Ytranslators.
 17. The apparatus of claim 1, wherein the substratepositioning system is operable to move the substrate support in adirection perpendicular to the top surface of the substrate support. 18.The apparatus of claim 1, wherein the second chamber is formed fromquartz or ceramic.
 19. The apparatus of claim 1, further comprising asubstrate heater mounted in the substrate support.
 20. The apparatus ofclaim 19, wherein the substrate heater is operable to vary a temperatureof the substrate in a combinatorial manner during the PECVD and thePEALD of different ones of the plurality of site-isolated regions.